Different injection types are required depending on what's being injected and why. Injections into the muscle (Intramuscular aka IM) are generally a way of *slowly* introducing something to the body. Immunizations are a classic example of IM injections for just that reason. Muscles still have blood vessels, and lymphatic drainage, so over time whatever is injected into them will be disseminated through the body.
By contrast if you want to rapidly delivery a drug to someone's circulatory system, maybe a sedative or something simple like glucose to reverse a diabetic attack, then you want to access a vein.
Pretty much, you can think about it this way in order from "Quickest to enter the blood" to "Slowest":
IV, IO (into bone) and anything into an artery is FAST. This is rapid access, and high volume potential.
IM: Slower than IV/IO/Etc, but muscles are still full of blood vessels so anything you inject into a muscle is going to reach the blood supply over hours.
Subcutaneous: The slowest, subcutaneous tissue is poorly supplied with blood vessels compared to muscles, so this is often used when you want to keep things localized. For a Tuberculosis test for example, an allergy test, or anything similar you want a localized reaction, not a systemic one.
>n think about it this way in order from "Quickest to enter the blood" to "Slowest":
>
>IV, IO (into bone) and anything into an artery is FAST. This is rapid access, and high volume potential.
>
>IM: Slower than IV/IO/Etc, but muscles are still full of blood vessels so anything you inject into a muscle is going to reach the blood supply over hours.
>
>Subcutaneous: The slowest, subcutaneous tissue is poor
so why are fertility med injections (FSH, LH) sub-cutaneous? That's not specifically local or slow.
Additionally, would it not also be correct that a vaccine doesn’t even need to be disseminated? As long as the immune system encounters it in one muscle, the response will be available in all of them.
Sometimes IM is also very painful. Like if you miss the vein when injecting methamphetamine it’s gonna burn like a motherfucker for a while. I’m not sure how long exactly but probably more than you’d like.
Different injection types are required depending on what's being injected and why. Injections into the muscle (Intramuscular aka IM) are generally a way of *slowly* introducing something to the body. Immunizations are a classic example of IM injections for just that reason. Muscles still have blood vessels, and lymphatic drainage, so over time whatever is injected into them will be disseminated through the body. By contrast if you want to rapidly delivery a drug to someone's circulatory system, maybe a sedative or something simple like glucose to reverse a diabetic attack, then you want to access a vein.
Is a subcutaneous injection somewhere in between then?
Pretty much, you can think about it this way in order from "Quickest to enter the blood" to "Slowest": IV, IO (into bone) and anything into an artery is FAST. This is rapid access, and high volume potential. IM: Slower than IV/IO/Etc, but muscles are still full of blood vessels so anything you inject into a muscle is going to reach the blood supply over hours. Subcutaneous: The slowest, subcutaneous tissue is poorly supplied with blood vessels compared to muscles, so this is often used when you want to keep things localized. For a Tuberculosis test for example, an allergy test, or anything similar you want a localized reaction, not a systemic one.
A tuberculosis test is intradermal, not subcutaneous.
>n think about it this way in order from "Quickest to enter the blood" to "Slowest": > >IV, IO (into bone) and anything into an artery is FAST. This is rapid access, and high volume potential. > >IM: Slower than IV/IO/Etc, but muscles are still full of blood vessels so anything you inject into a muscle is going to reach the blood supply over hours. > >Subcutaneous: The slowest, subcutaneous tissue is poor so why are fertility med injections (FSH, LH) sub-cutaneous? That's not specifically local or slow.
That's so clear, thank you.
Additionally, would it not also be correct that a vaccine doesn’t even need to be disseminated? As long as the immune system encounters it in one muscle, the response will be available in all of them.
Sometimes IM is also very painful. Like if you miss the vein when injecting methamphetamine it’s gonna burn like a motherfucker for a while. I’m not sure how long exactly but probably more than you’d like.